Draft device for locomotives



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(No'ModeL) NEILSON. Draft Device for Locomotives.

Patented Jan. 18,1881.

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G. NEILSON. Draft Device for Locomotives.

No. 236,716. Patented Jan. 18,1881,

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Q INVENTUR w w PEIERS, PHOTO-UTHOGRAPHER, WASmNGTON, D 04 UNITED STATES GEORGE NEILSON, OF CHELSEA, MASSACHUSETTS.

DRAFT DEVICE FOR LOCOMOTIVES.

SPECIFICATION formingpart of Letters Patent No. 236,716, dated January 18, 1881.

Application filed March 11, 1880.

To all whom it may concern Be it known that 1, GEORGE NniLsoN, of Chelsea, in the county of Suffolk and State of Massachusetts, have invented a new and useful Draft Device for Locomotive and other Boilers, of which the following is a specificatwo.

My invention relates to that class of boilers in which one or more of the air-supplying devices works in variable duplicate functionsa. 6., the device furnishes a varying amount of fresh air to the fire, and, at the same time and through about the same instrumentalities, a varying quantity of the products of incomplete combustion, the two operations co-acting,but in variable degrees, in relation to each other. For instance, in some cases the amount of pure air may much exceed the products of combustion, and in other cases the terms are reversed; but in all cases with my invention the relative amounts may be accurately controlled.

My invention consists in connecting, with the under side of a boiler, a tube, one end of which is exposed to the open air while the other opens into a distributing-chamber near the fire-box, the air flowing from the distributing-chamber under a flange and in the immediate vicinity of the deflector and a freshair opening, so that the air that flows in under the grate from this source is delivered in a fiat sheet and well distributed over the under side of the fire-grate surface. The air-tube above mentioned has openings into the smokechamber, and is provided with a number of dampers and deflectors for the purpose of drawing in volumes of fresh air or the products of incomplete combustion, and also for the purpose of controlling the relative amounts of the same. This system can be best understood by reference to the drawings and specification.

In the drawings, Figure 1 is a vertical longitudinal section of a locomotive-boiler having my invention attached. Fig. 2 is a vertical cross-section through the fire-box. Fig. 3 is a cross vertical section taken through the smoke-chamber air-induction tube; also showing the chamber S and damper N.

The boiler A, fire-box A, and smoke-chamber B are made in the usual manner.

(No model.)

I will now proceed to describe the parts in i which my invention is embraced.

D D is an air-tube having an opening in front and a place of discharge at D. The chamber S, into which the air-tube D D discharges, extends along the back of the firebox, as shown in Fig. 3, so that the infiowing air may be distributed along the entire width of the grate-surface.

H, Fig. 1, is a deflector, located as shown, and is intended to contract the infiowin g current of air, and to thus causea partial vacuum behind it at M. The object of creating a partial vacuum at M is to draw the products of incomplete combustion from the smoke-chamber B and to pass them, mixed with fresh air, to the ash-pit O, and thence to the fire, as indicated by the arrows.

D is a deflecting-plate, placed as shown in Figs. 1 and 2, and it serves to cause a partial vacuum in the space S whenever the front damper, N, is open, thus assisting the flow of products of incomplete combustion from the smoke-chamber.

K, Fig. 1, is a damper for the purpose of closing, or partly closing, the orifice between the smoke-chamber B and the air-tube D D. This damper K. being connected by a rod, (see Fig. 1,) connects the damper L in the smokestack to the damper K, so that the two dampers L and K move together. These may be operated by a rod or cord. extending to the cab of the engines.

E, Figs. 1 and 3, is an orifice made in the tube D D for the purpose of admitting air and for increasing the velocity of the current. This orifice has a valve, E, to regulate the flow of the incoming air.

T, Fig. 1, is a pipe for the introduction of steam into the current of air, and thus warm it and otherwise facilitate the draft.

The damper N, (see Figs. 1 and 3,) when open, serves to admit fresh air under the grates. The deflector D (see Fig. 1) is so placed as to prevent the fresh cold air from directly striking the grate-bars; and it also serves to form a partial vacuum and thus draw air from the chamber S to intermingle with the fresh air that flows in when the damper N is open.

The damper L in the smoke-stack is used to check the direct draft, and thus cause a circucombination with the air-space S and deflector D, all operating together substantially as described, and for the purpose set forth.

2. In a locomotive-boiler, the damper L,connecting-rod 7c, and damper K, in combination with the air-tube D D, air-space S, and ashpit C, substantially as described, and for the purpose set forth.

GEORGE NEILSON.

Witnesses:

FRANK G. PARKER, JAMES A. GRocKER. 

